The increasing prevalence of sexually transmitted diseases (STDs) is a serious public health problem affecting physical contact, sexual activity, and relationships between individuals.
Examples of STDs include those caused by viral infection such as human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS), herpes simplex types 1 and 2, human papillomavirus (HPV), and hepatitis B; those caused by bacterial infection such as gonorrhea, syphilis, chancroid, and chlamydia; and those caused by infection of other microorganisms such as trichomoniasis and candidiasis. Of particular concern is HIV/AIDS, a fatal disease which presently infects millions of people worldwide and is considered pandemic by the World Health Organization (WHO).
Sexually active females who are susceptible to STD transmissions at the same time run high risks of unwanted pregnancy.
Surfactants have been used as active ingredients in contraceptive compositions. It is also known that some surfactants, such as nonoxynol-9 and octoxynol-9, demonstrated inhibitory activity on HIV infection. For example, WO00/72839 describes a spermicidally and virucidally effective formulation for vaginal application that comprises benzalkonium chloride and octoxynol-9.
However, frequent use of nonoxynol-9 as a vaginal contraceptive/microbicide has been associated with an increased risk of vaginal or cervical infection, irritation, or ulceration (Niruthisard et al., Sex Transm Dis. 18:176-79 (1991); Rekart, Defic Syndr. 5:425-27 (1992); Roddy et al., Int J STD & HIV. 4:165-70 (1993); Weir et al., Genitourin Med. 71:78-81 (1995)) which can enhance the susceptibility of the ectocervical epithelium and the endocervical mucosa to HIV-1 infection (Augenbraun et al. Infect Dis Clin North Am. 8:439-48 (1994); Weir et al., Genitourin Med. 71:78-81 (1995); Kreiss, JAMA. 268:477-82 (1992)).
From 1996 to 2000, a clinical trial sponsored by the United Nation (UN) followed nearly 1,000 sex workers in Africa who used nonoxynol-9 or a placebo. The HIV infection rate among those using nonoxynol-9 was about 50% higher than those who used the placebo.
Compositions and formulations comprising active ingredients that are not surfactants have also been developed for preventing the spread of STDs. CN 1517116 describes a composition comprising five herbal extracts from Cnidium monnieri, Artemisia argyi, Sophoraflavescens, Isitidis tinctoria, and Brucea javanica. US2006/0062866 describes a starch-pomegranate juice complex. WO2007/074478 describes condoms, gels, creams and vaginal pessaries comprising Azadirachta indica extract and/or Carica papaya extract. US2009/0004294 describes a lubricating composition comprising a colloidal metal. US2012/0046556 describes a composition comprising a dental irritant.
There remains a need for the development of compositions that are effective in preventing transmission of STDs and/or conception and, when used in body orifices and/or on genitalia, exhibit low systemic and/or local toxicity at the target mucosal membranes.